The introduction of non-indigenous species (NIS) to exotic habitats can have tremendous impacts on native biodiversity, food webs, and ecosystem services. One globally distributed aquatic NIS is the hydrozoan Craspedacusta sowerbii Lankester, 1880. The species’ northern distribution boundary in North America is situated in British Columbia (BC), Canada. It is thus of paramount interest to understand its ecology in this warming invaded habitat, allowing for insights into other regions. Specimens of the genus Craspedacusta have been reported in 34 freshwater systems since August 1990. These reported locations are generally shallow (<10 m), most often of natural origin, and have a small surface area (<0.1 km2). We observed an exponential trend of medusa observations from 1990 till the end of the 2020s. The first seasonal records are in July and the latest in October, with peak sightings reported in August and September. After 2012, regional temperature anomalies during July and August were mostly positive, which overlaps with the period of the majority of reported C. sowerbii sightings. Until this day, all examined medusae are males.
{"title":"Spatiotemporal distribution of the non-indigenous peach blossom jellyfish Craspedacusta sowerbii in British Columbia, Canada","authors":"F. Lüskow, Evgeny A. Pakhomov","doi":"10.1139/cjz-2024-0007","DOIUrl":"https://doi.org/10.1139/cjz-2024-0007","url":null,"abstract":"The introduction of non-indigenous species (NIS) to exotic habitats can have tremendous impacts on native biodiversity, food webs, and ecosystem services. One globally distributed aquatic NIS is the hydrozoan Craspedacusta sowerbii Lankester, 1880. The species’ northern distribution boundary in North America is situated in British Columbia (BC), Canada. It is thus of paramount interest to understand its ecology in this warming invaded habitat, allowing for insights into other regions. Specimens of the genus Craspedacusta have been reported in 34 freshwater systems since August 1990. These reported locations are generally shallow (<10 m), most often of natural origin, and have a small surface area (<0.1 km2). We observed an exponential trend of medusa observations from 1990 till the end of the 2020s. The first seasonal records are in July and the latest in October, with peak sightings reported in August and September. After 2012, regional temperature anomalies during July and August were mostly positive, which overlaps with the period of the majority of reported C. sowerbii sightings. Until this day, all examined medusae are males.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141919537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The introduction of non-indigenous species (NIS) to exotic habitats can have tremendous impacts on native biodiversity, food webs, and ecosystem services. One globally distributed aquatic NIS is the hydrozoan Craspedacusta sowerbii Lankester, 1880. The species’ northern distribution boundary in North America is situated in British Columbia (BC), Canada. It is thus of paramount interest to understand its ecology in this warming invaded habitat, allowing for insights into other regions. Specimens of the genus Craspedacusta have been reported in 34 freshwater systems since August 1990. These reported locations are generally shallow (<10 m), most often of natural origin, and have a small surface area (<0.1 km2). We observed an exponential trend of medusa observations from 1990 till the end of the 2020s. The first seasonal records are in July and the latest in October, with peak sightings reported in August and September. After 2012, regional temperature anomalies during July and August were mostly positive, which overlaps with the period of the majority of reported C. sowerbii sightings. Until this day, all examined medusae are males.
{"title":"Spatiotemporal distribution of the non-indigenous peach blossom jellyfish Craspedacusta sowerbii in British Columbia, Canada","authors":"F. Lüskow, Evgeny A. Pakhomov","doi":"10.1139/cjz-2024-0007","DOIUrl":"https://doi.org/10.1139/cjz-2024-0007","url":null,"abstract":"The introduction of non-indigenous species (NIS) to exotic habitats can have tremendous impacts on native biodiversity, food webs, and ecosystem services. One globally distributed aquatic NIS is the hydrozoan Craspedacusta sowerbii Lankester, 1880. The species’ northern distribution boundary in North America is situated in British Columbia (BC), Canada. It is thus of paramount interest to understand its ecology in this warming invaded habitat, allowing for insights into other regions. Specimens of the genus Craspedacusta have been reported in 34 freshwater systems since August 1990. These reported locations are generally shallow (<10 m), most often of natural origin, and have a small surface area (<0.1 km2). We observed an exponential trend of medusa observations from 1990 till the end of the 2020s. The first seasonal records are in July and the latest in October, with peak sightings reported in August and September. After 2012, regional temperature anomalies during July and August were mostly positive, which overlaps with the period of the majority of reported C. sowerbii sightings. Until this day, all examined medusae are males.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141919090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samuel R. Jolly, J. Gilbert, J. Woodford, Dan Eklund, Jonathan N Pauli
Organisms in seasonal environments respond to both resources in the summer and environmental conditions in winter. Small mammals, in particular, respond quickly to changes in their environment, with many species reliant on the thermal refuge of the subnivium in the winter. However, there has been little research exploring how resources and cold exposure drive the seasonal dynamics of small mammal populations. We studied the populations of 3 subnivium-specialist small mammal species in seasonally snow-covered forests in Wisconsin USA across 5 years during summer and winter. In summer, mast availability and canopy cover governed white-footed mouse (Peromyscus leucopus (Rafinesque, 1818)) populations, coarse woody debris drove short-tailed shrew (Blarina brevicauda (Say, 1823)) populations, and rainfall influenced red-backed vole (Myodes gapperi (Vigors, 1830)) abundance. Dietary analysis via stable isotopes revealed that shrews primarily consumed arthropods, and mice predominately consumed hard mast despite interannual changes in availability. In winter, white-footed mice and red-backed vole abundances were negatively related to cold exposure. Short-tailed shrew winter population was positively related to their abundances the previous summer. These small mammals responded to species-specific drivers during the growing and snow seasons. Consequently, shorter snow seasons from climate change appear to be restructuring communities by creating a less hospitable environment for winter-adapted species, likely contributing to their regional declines.
{"title":"Seasonal dynamics of small mammal populations: resource availability and cold exposure interact to govern abundance","authors":"Samuel R. Jolly, J. Gilbert, J. Woodford, Dan Eklund, Jonathan N Pauli","doi":"10.1139/cjz-2024-0020","DOIUrl":"https://doi.org/10.1139/cjz-2024-0020","url":null,"abstract":"Organisms in seasonal environments respond to both resources in the summer and environmental conditions in winter. Small mammals, in particular, respond quickly to changes in their environment, with many species reliant on the thermal refuge of the subnivium in the winter. However, there has been little research exploring how resources and cold exposure drive the seasonal dynamics of small mammal populations. We studied the populations of 3 subnivium-specialist small mammal species in seasonally snow-covered forests in Wisconsin USA across 5 years during summer and winter. In summer, mast availability and canopy cover governed white-footed mouse (Peromyscus leucopus (Rafinesque, 1818)) populations, coarse woody debris drove short-tailed shrew (Blarina brevicauda (Say, 1823)) populations, and rainfall influenced red-backed vole (Myodes gapperi (Vigors, 1830)) abundance. Dietary analysis via stable isotopes revealed that shrews primarily consumed arthropods, and mice predominately consumed hard mast despite interannual changes in availability. In winter, white-footed mice and red-backed vole abundances were negatively related to cold exposure. Short-tailed shrew winter population was positively related to their abundances the previous summer. These small mammals responded to species-specific drivers during the growing and snow seasons. Consequently, shorter snow seasons from climate change appear to be restructuring communities by creating a less hospitable environment for winter-adapted species, likely contributing to their regional declines.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141822250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ian Stirling, Lynne E. Burns, Eric V. Regehr, Kristin L. Laidre, C. Spencer
During 17 spring and summer field seasons between 1973 and 1999, we documented 220 bouts of nursing by dependent polar bear ( Ursus maritimus Phipps, 1774) cubs at Radstock Bay, Nunavut, Canada. The overall mean duration of nursing bouts for cubs-of-the-year (COY) and yearlings (YRLG) litters was 7.1 min (standard deviation (SD) = 3.3, range = 1–23). Mean nursing bout durations of one- and two-cub litters of COY and YRLG in spring and summer seasons ranged from 6.09 to 7.78 min and from 5.00 to 9.18 min, respectively. The overall mean duration of inter-nursing intervals for COY and YRLG litters was 5.7 h (SD = 4.9, range = 0.0–35.0). The mean inter-nursing interval for one-cub litters was 6.4 h (SD = 4.6, range = 0.0–20.2) and for two-cub litters was 5.1 h (SD = 5.1, range = 0.0–35.0). We found no evidence for effects of season or cub age class on nursing behavior. We found weak evidence that two-cub litters nurse slightly longer than one-cub litters, potentially reflecting reduced nursing efficiency due to sibling rivalry. There was neither evidence for diel patterns in nursing behavior nor a detectable relationship between the cessation of nursing and the onset of hunting or sleeping by the adult female.
{"title":"Nursing behavior of wild polar bears in the Canadian High Arctic","authors":"Ian Stirling, Lynne E. Burns, Eric V. Regehr, Kristin L. Laidre, C. Spencer","doi":"10.1139/cjz-2024-0001","DOIUrl":"https://doi.org/10.1139/cjz-2024-0001","url":null,"abstract":"During 17 spring and summer field seasons between 1973 and 1999, we documented 220 bouts of nursing by dependent polar bear ( Ursus maritimus Phipps, 1774) cubs at Radstock Bay, Nunavut, Canada. The overall mean duration of nursing bouts for cubs-of-the-year (COY) and yearlings (YRLG) litters was 7.1 min (standard deviation (SD) = 3.3, range = 1–23). Mean nursing bout durations of one- and two-cub litters of COY and YRLG in spring and summer seasons ranged from 6.09 to 7.78 min and from 5.00 to 9.18 min, respectively. The overall mean duration of inter-nursing intervals for COY and YRLG litters was 5.7 h (SD = 4.9, range = 0.0–35.0). The mean inter-nursing interval for one-cub litters was 6.4 h (SD = 4.6, range = 0.0–20.2) and for two-cub litters was 5.1 h (SD = 5.1, range = 0.0–35.0). We found no evidence for effects of season or cub age class on nursing behavior. We found weak evidence that two-cub litters nurse slightly longer than one-cub litters, potentially reflecting reduced nursing efficiency due to sibling rivalry. There was neither evidence for diel patterns in nursing behavior nor a detectable relationship between the cessation of nursing and the onset of hunting or sleeping by the adult female.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141820767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multiple brooding is an important component of reproductive success in many birds and the frequency of this behaviour has been linked to intrinsic (e.g., age, experience) and extrinsic factors (e.g., weather, food availability). When extrinsic factors drive multiple brooding, it may be possible to identify conservation actions to support multiple-brooded species at risk. The Barn Swallow (Hirundo rustica Linnaeus, 1758), is a multiple-brooded aerial insectivore, currently listed as Threatened on Canada’s Species at Risk Act. We examined how weather, landcover, the presence of livestock and metal roofs (with associated heat) above nests affected the likelihood of multiple brooding in Barn Swallows nesting in Nova Scotia and New Brunswick, Canada. We found that sites with a lower proportion of open habitats, including pastures, hayfields, and lawns, within the typical foraging range (i.e., 400 m) of nests, were associated with a higher probability of multiple brooding. Also, multiple brooding may be less likely in windy conditions. We found no effect of proportion of other landcover types, weather conditions, livestock or metal roofs above nests. When possible, decreasing the proportion of open habitats around breeding sites could result in higher rates of multiple brooding, and in turn, help slow population declines.
{"title":"Determinants of Multiple Brooding in Barn Swallows (Hirundo rustica) in Atlantic Canada","authors":"H. A. Mann, T. L. Imlay, Marty L. Leonard","doi":"10.1139/cjz-2024-0060","DOIUrl":"https://doi.org/10.1139/cjz-2024-0060","url":null,"abstract":"Multiple brooding is an important component of reproductive success in many birds and the frequency of this behaviour has been linked to intrinsic (e.g., age, experience) and extrinsic factors (e.g., weather, food availability). When extrinsic factors drive multiple brooding, it may be possible to identify conservation actions to support multiple-brooded species at risk. The Barn Swallow (Hirundo rustica Linnaeus, 1758), is a multiple-brooded aerial insectivore, currently listed as Threatened on Canada’s Species at Risk Act. We examined how weather, landcover, the presence of livestock and metal roofs (with associated heat) above nests affected the likelihood of multiple brooding in Barn Swallows nesting in Nova Scotia and New Brunswick, Canada. We found that sites with a lower proportion of open habitats, including pastures, hayfields, and lawns, within the typical foraging range (i.e., 400 m) of nests, were associated with a higher probability of multiple brooding. Also, multiple brooding may be less likely in windy conditions. We found no effect of proportion of other landcover types, weather conditions, livestock or metal roofs above nests. When possible, decreasing the proportion of open habitats around breeding sites could result in higher rates of multiple brooding, and in turn, help slow population declines.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141829578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Ralls, Tammy R. Wilbert, Brian Cypher, Christine Van Horn Job, Jesus E Maldonado
Smaller canids, such as most foxes, individually hunt small prey, and therefore social groups typically consist of just a mated pair. However, these smaller canids occasionally form groups in which the members have been presumed to be genetically or socially related. We studied social and genetic relationships among urban San Joaquin kit fox (Vulpes macrotis mutica Merriam, 1888) groups in Bakersfield, California. Of 59 groups, 42.4% had extra adults in addition to the parents. Foxes were field classified as either mothers, fathers, helpers (extra adults), or pups. We then assessed relatedness of foxes within social groups using 11 microsatellites in DNA from tissue or hair samples. Mated pairs were significantly less related than mothers and helpers, with fathers and helpers being intermediate. Twelve pairs of females were mother-daughter dyads but we also found two cases of sisters and two cases where the females were unrelated. Pups were always related to a female identified as their mother. Father-pup pairs were less related than mother-pup pairs, with helper-pup pairs being intermediate. The extra-pair paternity rate (multiple fathers per litter) was 39%. The social flexibility exhibited by kit foxes may increase their resiliency to marked fluctuations in resource availability thereby reducing extinction risk.
{"title":"Social and genetic relationships among individuals in urban kit fox social groups","authors":"K. Ralls, Tammy R. Wilbert, Brian Cypher, Christine Van Horn Job, Jesus E Maldonado","doi":"10.1139/cjz-2024-0057","DOIUrl":"https://doi.org/10.1139/cjz-2024-0057","url":null,"abstract":"Smaller canids, such as most foxes, individually hunt small prey, and therefore social groups typically consist of just a mated pair. However, these smaller canids occasionally form groups in which the members have been presumed to be genetically or socially related. We studied social and genetic relationships among urban San Joaquin kit fox (Vulpes macrotis mutica Merriam, 1888) groups in Bakersfield, California. Of 59 groups, 42.4% had extra adults in addition to the parents. Foxes were field classified as either mothers, fathers, helpers (extra adults), or pups. We then assessed relatedness of foxes within social groups using 11 microsatellites in DNA from tissue or hair samples. Mated pairs were significantly less related than mothers and helpers, with fathers and helpers being intermediate. Twelve pairs of females were mother-daughter dyads but we also found two cases of sisters and two cases where the females were unrelated. Pups were always related to a female identified as their mother. Father-pup pairs were less related than mother-pup pairs, with helper-pup pairs being intermediate. The extra-pair paternity rate (multiple fathers per litter) was 39%. The social flexibility exhibited by kit foxes may increase their resiliency to marked fluctuations in resource availability thereby reducing extinction risk.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141656537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Porreca, Neil Rude, Kyle Broadway, Joseph Parkos
Sympatric black crappie (Pomoxis nigromaculatus Lesueur in Cuvier and Valenciennes, 1829) and white crappie (P. annularis Rafinesque, 1818) often differ in ecological performance, such that white crappie outnumber black crappie in turbid waterbodies and black crappie predominate in clear waters with abundant cover. Recent work suggests this performance difference is driven by juvenile white crappie having a limnetic body form and juvenile black crappie having a littoral body form, resulting in differential predation mortality between the species within open-water and vegetated environments. We tested whether these morphologies also lead to interspecific differences in foraging efficiency between the congeners in structure and open water. Juvenile black crappie spent more time pursuing fish prey than white crappie across all trials, suggesting that energetic gains of piscivory may differ between species. However, both species had similar capture efficiencies when attacking fathead minnows (Pimephales promelas Rafinesque, 1820) within vegetated and open-water habitats. We conclude that variation in morphology between juvenile black crappie and white crappie does not have a large influence on foraging efficiency, at least on fish prey, in dense cover or open water, and suggest their performance in sympatry is likely not driven by predatory capabilities at the onset of piscivory within these different environmental contexts. Instead, the relationship between morphology and predator evasion may drive the distribution and relative abundance of crappie species within sympatric populations.
同域的黑螃蟹（Pomoxis nigromaculatus Lesueur in Cuvier and Valenciennes, 1829）和白螃蟹（P. annularis Rafinesque, 1818）通常在生态表现上有所不同，例如，在浑浊的水体中，白螃蟹的数量超过黑螃蟹，而在有丰富覆盖物的清澈水体中，黑螃蟹占优势。最近的研究表明，这种生态表现差异是由于白螃蟹幼鱼具有边缘体型，而黑螃蟹幼鱼具有沿岸体型，从而导致开放水域和植被环境中不同物种的捕食死亡率不同。我们测试了这些形态是否也会导致同种鱼类在结构和开放水域中觅食效率的种间差异。在所有试验中，幼年黑螃蟹比白螃蟹花更多时间捕食鱼类猎物，这表明不同物种捕食鱼类获得的能量收益可能不同。然而，在有植被和开阔水域生境中，两种鱼类在攻击黑头鲦（Pimephales promelas Rafinesque, 1820）时的捕获效率相似。我们的结论是，黑螃蟹和白螃蟹幼鱼之间的形态差异不会对觅食效率产生很大影响，至少不会影响它们在茂密植被或开阔水域中捕食鱼类猎物的效率。相反，形态与躲避捕食者之间的关系可能会驱动螃蟹物种在同域种群中的分布和相对丰度。
{"title":"Do interspecific differences in morphology influence foraging efficiency of juvenile crappie?","authors":"A. Porreca, Neil Rude, Kyle Broadway, Joseph Parkos","doi":"10.1139/cjz-2024-0030","DOIUrl":"https://doi.org/10.1139/cjz-2024-0030","url":null,"abstract":"Sympatric black crappie (Pomoxis nigromaculatus Lesueur in Cuvier and Valenciennes, 1829) and white crappie (P. annularis Rafinesque, 1818) often differ in ecological performance, such that white crappie outnumber black crappie in turbid waterbodies and black crappie predominate in clear waters with abundant cover. Recent work suggests this performance difference is driven by juvenile white crappie having a limnetic body form and juvenile black crappie having a littoral body form, resulting in differential predation mortality between the species within open-water and vegetated environments. We tested whether these morphologies also lead to interspecific differences in foraging efficiency between the congeners in structure and open water. Juvenile black crappie spent more time pursuing fish prey than white crappie across all trials, suggesting that energetic gains of piscivory may differ between species. However, both species had similar capture efficiencies when attacking fathead minnows (Pimephales promelas Rafinesque, 1820) within vegetated and open-water habitats. We conclude that variation in morphology between juvenile black crappie and white crappie does not have a large influence on foraging efficiency, at least on fish prey, in dense cover or open water, and suggest their performance in sympatry is likely not driven by predatory capabilities at the onset of piscivory within these different environmental contexts. Instead, the relationship between morphology and predator evasion may drive the distribution and relative abundance of crappie species within sympatric populations.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sofia Sabbagh, Vincent Mélançon, Sophie Breton, S. Binning
Host populations can vary in the prevalence and intensity of their parasites, which may influence the impacts of infection on host physiology and health. Parasite-induced effects on hosts may be due to underlying changes in cellular energy metabolism, predominantly driven by the mitochondria. However, limited research has been conducted on understanding variation in host-parasite interactions across populations. We sampled three wild populations of pumpkinseed sunfish (Lepomis gibbosus (Linnaeus, 1758)), two of which are infected by cestodes, to study correlations among infection intensity, host body condition and key metabolic enzyme activities in liver tissue. In both infected populations, cestode infection was associated with reduced hepatic lipid metabolism and increased hepatic lactic fermentation. Interestingly, Lake Cromwell fish showed a decrease in body condition, electron transport system activity and antioxidant activity with cestode intensity, whereas the contrary was observed for Lake Long fish. This suggests that Lake Long fish could be boosting their immune system and food intake to better tolerate infection, unlike Cromwell fish. This study not only highlights how different populations can vary in their response to parasite infections but also the importance of accounting for infection when studying animal physiology.
{"title":"Differences in body condition and hepatic cellular metabolism among distinct populations of cestode infected pumpkinseed sunfish (Lepomis gibbosus)","authors":"Sofia Sabbagh, Vincent Mélançon, Sophie Breton, S. Binning","doi":"10.1139/cjz-2023-0169","DOIUrl":"https://doi.org/10.1139/cjz-2023-0169","url":null,"abstract":"Host populations can vary in the prevalence and intensity of their parasites, which may influence the impacts of infection on host physiology and health. Parasite-induced effects on hosts may be due to underlying changes in cellular energy metabolism, predominantly driven by the mitochondria. However, limited research has been conducted on understanding variation in host-parasite interactions across populations. We sampled three wild populations of pumpkinseed sunfish (Lepomis gibbosus (Linnaeus, 1758)), two of which are infected by cestodes, to study correlations among infection intensity, host body condition and key metabolic enzyme activities in liver tissue. In both infected populations, cestode infection was associated with reduced hepatic lipid metabolism and increased hepatic lactic fermentation. Interestingly, Lake Cromwell fish showed a decrease in body condition, electron transport system activity and antioxidant activity with cestode intensity, whereas the contrary was observed for Lake Long fish. This suggests that Lake Long fish could be boosting their immune system and food intake to better tolerate infection, unlike Cromwell fish. This study not only highlights how different populations can vary in their response to parasite infections but also the importance of accounting for infection when studying animal physiology.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141679451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leila M. López, Agustín I. Quaglia, Santiago M. Benitez-Vieyra, V. Cantarelli, Marina Flavia Ponzio, Diego Javier Valdez
The mechanisms regulating plumage coloration appear to be phylogenetically conserved in avian species: the plesiomorphic character state is estrogen-dependent regulation while testosterone, luteinizing hormone and non-hormonal control are derived states. Limited data exist on the underlying regulatory processes of sexual dichromatism in the Eared Dove (Zenaida auriculata des Murs, 1847). Since the Columbiformes order is close to basal branches, we hypothesised that estrogen and testosterone play a central role in the regulation of crown plumage coloration in the Eared Dove. To test this, we subjected adult males to a forced molt accompanied by an exogenous increase of estradiol and testosterone to determine whether the presence of these hormones during molting modified the spectrophotometric characteristics of the plumage. No significant differences were found between treatments and controls in the colorimetric variables hue, ultraviolet saturation and brightness. Similarly, the avian visual model showed no perceptible changes in chromatic and achromatic signals in the individual male adults. We also analysed the effects of estrogen and testosterone on the growth speed of the new feathers. The hormone-treated groups increased in the speed of molting compared to the control group. These results suggest that the Eared Dove is an exception to basal branch models: rather than regulating coloration, sex hormones speed up the growth of the new feathers.
鸟类物种的羽色调节机制似乎在系统发育上是保守的：多形性特征状态是雌激素依赖性调节，而睾酮、黄体生成素和非激素控制则是衍生状态。有关耳鸽（Zenaida auriculata des Murs，1847 年）性双色性的基本调节过程的数据有限。由于哥伦布形目接近基干分支，我们假设雌激素和睾酮在耳鸽冠羽着色的调控过程中起着核心作用。为了验证这一假设，我们对成年雄鸟进行了强制蜕皮，同时外源性增加雌二醇和睾酮，以确定蜕皮期间这些激素的存在是否会改变羽色的分光光度特性。在色调、紫外线饱和度和亮度等色度变量方面，处理组和对照组之间没有发现明显差异。同样，鸟类视觉模型显示，雄性成鸟个体的色度和消色差信号没有明显变化。我们还分析了雌激素和睾酮对新羽毛生长速度的影响。与对照组相比，激素处理组的蜕皮速度有所提高。这些结果表明，耳廓鸽是基枝模型的一个例外：性激素不是调节颜色，而是加速新羽毛的生长。
{"title":"Contrary to phylogenetic predictions, crown coloration of the Eared Dove is not regulated by sex hormones","authors":"Leila M. López, Agustín I. Quaglia, Santiago M. Benitez-Vieyra, V. Cantarelli, Marina Flavia Ponzio, Diego Javier Valdez","doi":"10.1139/cjz-2024-0023","DOIUrl":"https://doi.org/10.1139/cjz-2024-0023","url":null,"abstract":"The mechanisms regulating plumage coloration appear to be phylogenetically conserved in avian species: the plesiomorphic character state is estrogen-dependent regulation while testosterone, luteinizing hormone and non-hormonal control are derived states. Limited data exist on the underlying regulatory processes of sexual dichromatism in the Eared Dove (Zenaida auriculata des Murs, 1847). Since the Columbiformes order is close to basal branches, we hypothesised that estrogen and testosterone play a central role in the regulation of crown plumage coloration in the Eared Dove. To test this, we subjected adult males to a forced molt accompanied by an exogenous increase of estradiol and testosterone to determine whether the presence of these hormones during molting modified the spectrophotometric characteristics of the plumage. No significant differences were found between treatments and controls in the colorimetric variables hue, ultraviolet saturation and brightness. Similarly, the avian visual model showed no perceptible changes in chromatic and achromatic signals in the individual male adults. We also analysed the effects of estrogen and testosterone on the growth speed of the new feathers. The hormone-treated groups increased in the speed of molting compared to the control group. These results suggest that the Eared Dove is an exception to basal branch models: rather than regulating coloration, sex hormones speed up the growth of the new feathers.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141682238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anna N. Malesis, R. M. Windell, Carmen M Vanbianci, Laura Prugh
Apex predators exert suppressive effects on mesocarnivores; however, they also provide important carrion subsidies. Optimal foraging theory predicts that individuals respond to resource competition by using high value resources, while competition theory predicts that individuals respond by partitioning resources. This study investigated how the return of wolves (Canis lupus Linneas, 1758) to Washington state impacted the diet of a subordinate carnivore—the coyote (Canis latrans Say, 1823). We collected coyote scats from two areas of northern Washington with differing wolf densities and used traditional analysis of undigested remains to infer diet. We tested for differences in the volumes of prey categories, the proportion of ungulate prey that was scavenged, and diet diversity between seasons, study sites, and inside and outside of wolf pack territories. Coyote scats contained more adult ungulate remains inside of wolf pack territories (27%) compared to outside (14%), while seeds and berries were more commonly consumed outside of wolf pack territories (23%) than inside of wolf pack territories (4%). These findings suggest that coyotes are taking advantage of wolf kills to increase ungulate carrion consumption, as predicted by optimal foraging theory, which may substantially affect plant and wildlife communities as wolves continue to recover and coyote diets shift in response.
{"title":"Coyotes take advantage of ungulate carrion subsidies as wolves recolonize Washington","authors":"Anna N. Malesis, R. M. Windell, Carmen M Vanbianci, Laura Prugh","doi":"10.1139/cjz-2024-0019","DOIUrl":"https://doi.org/10.1139/cjz-2024-0019","url":null,"abstract":"Apex predators exert suppressive effects on mesocarnivores; however, they also provide important carrion subsidies. Optimal foraging theory predicts that individuals respond to resource competition by using high value resources, while competition theory predicts that individuals respond by partitioning resources. This study investigated how the return of wolves (Canis lupus Linneas, 1758) to Washington state impacted the diet of a subordinate carnivore—the coyote (Canis latrans Say, 1823). We collected coyote scats from two areas of northern Washington with differing wolf densities and used traditional analysis of undigested remains to infer diet. We tested for differences in the volumes of prey categories, the proportion of ungulate prey that was scavenged, and diet diversity between seasons, study sites, and inside and outside of wolf pack territories. Coyote scats contained more adult ungulate remains inside of wolf pack territories (27%) compared to outside (14%), while seeds and berries were more commonly consumed outside of wolf pack territories (23%) than inside of wolf pack territories (4%). These findings suggest that coyotes are taking advantage of wolf kills to increase ungulate carrion consumption, as predicted by optimal foraging theory, which may substantially affect plant and wildlife communities as wolves continue to recover and coyote diets shift in response.","PeriodicalId":9484,"journal":{"name":"Canadian Journal of Zoology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141369920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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